The County of Apulia and Calabria, later the Duchy of Apulia and Calabria, was a Norman state founded by William of Hauteville in 1043 composed of the territories of Gargano, Capitanata, Apulia, Vulture, and most of Campania. It became a duchy when Robert Guiscard was raised to the rank of duke by Pope Nicholas II in 1059.

Apulia, also known by its Italian name Puglia, is a region of Italy, located in the southern peninsular section of the country, bordering the Adriatic Sea to the east, the Strait of Otranto and Ionian Sea to the southeast and the Gulf of Taranto to the south. The region comprises 19,345 square kilometers (7,469 sq mi), and its population is about four million people. It is bordered by the other Italian regions of Molise to the north, Campania to the west, and Basilicata to the southwest. The regional capital is Bari.